Vintage

The Roller World Training Center was a banked track derby "school" in Alameda, California. In 1974 it was one of only two such schools in the United States.  This patch was used in 1974-75.

• Bay Bombers

This is the team jacket and back patch of the San Francisco Bay Bombers.  According to one source the lettering was added in the 1980s during an attempt to reinvent the league as part of the IRSL (International Roller Skating League).

• Back Patch
• Southern Eagles

This is the team jacket and back patch of the Southern Eagles.  This was a warmup jacket from early 1972 (the team didn't last long) and is now in the property of the Roller Derby Hall of Fame.

• Thunderbirds

Back in the 1960s, there were two main competing groups (kinda-sorta of like the American and National leagues of baseball).  One trademarked the name Roller Derby, so the other used Roller Games.  As I understand it, the Rules were basically the same.  (I'd be curious what the differences were if anyone knows that level of detail.)  The Thunderbirds, or T-Birds as they were sometimes known, were one of the teams that made up Roller Games. 

• USA
• Trans Con Roller Derby

This is oldest known derby patch of which I'm aware.  Its history goes back to August 13, 1935 when Leo Seltzer held a month-long event in Chicago he called Transcontinental Roller Derby.  It was the simulation of a 3000-mile cross-country roller skating race in which 25 two-person (male-female) teams circled an oval banked track made of wood.  They would skate for 11.5 hours a day, and a team was disqualified if both members were off the track during skating times.  Only 9 of 25 teams finished the race.  He later took the sport to other venues around the United States.  Certain periods of time allowed physical contact between the skaters, a development that was highly popular with the audience.  He later reformed the event to minimize time and maximize contact, and a new sport was born.  This patch is likely from sometime in the mid-late 1930s.